This invention is directed generally to carton blanks and apparatus and method for forming the carton blanks and more particularly to apparatus and method for forming carton blanks that can be used to form leakproof cartons.
There are many supposedly leakproof cartons on the market today. These are formed using a variety of methods. Some of the cartons are designed to hold granular materials while others are designed to hold liquid materials. While some of these leakproof cartons have been successful, there is always a need for improvement.
This invention provides a leakproof carton having inner upper and lower closure panels formed from a fluid impervious material and not secured to the top or bottom panels of the carton.
In a preferred embodiment of the invention, the carton blank comprises a unitary sheet of relatively rigid material having an inner surface, an outer surface, a left side edge, a right side edge, a top edge and a bottom edge, with the left and right side edges being perpendicular to the top and bottom edges. The unitary sheet of relatively rigid material has a plurality of cut and fold lines for dividing the unitary sheet of relatively rigid material into a plurality of sidewall panel portions, a glue tab panel portion, and top and bottom panel portions extending outwardly from said sidewall panel portions. A first sheet of relatively flexible material is superposed over the inner surface of the top panel portions and portions of said sidewall panel portions adjacent to the fold lines between them and the top panel portions and a portion of the inner surface of the glue tab panel portion. Securing means, extending continuously between said right side edge and said left side edge, are provided for sealing and securing a portion of the first sheet of relatively flexible material to the inner surface of the portions of said sidewall panel portions adjacent to the fold lines between them and the top panel portions and to the portion of the glue tab panel portion.
A second sheet of relatively flexible material is superposed over the inner surface of the bottom panel portions, and other portions of the sidewall panel portions adjacent to the fold lines between them and the bottom panel portion and another portion of the inner surface of the glue tab panel portion. Securing means, extending continuously between said right side edge and said left side edge, are provided for sealing and securing a portion of the second sheet of relatively flexible material to the inner surface of the other portions of the sidewall panel portions adjacent to the fold lines between them and to the another portion of the glue tab panel portion. The first sheet of a relatively flexible material has an upper edge, a central body portion and a lower edge and the first securing means secure portions of the central body portion adjacent to the lower edge to the portions of the sidewall panel portions and the portion of the glue tab panel portion. The second sheet of a relatively flexible material has an upper edge, a central body portion and a lower edge and the second securing means secure portions of the central body portion adjacent to the upper edge to the other portions of the sidewall portions and the another portion of the glue tab panel portion. The first and second sheets of relatively flexible material and at least the exposed portions of the inner surface are fluid impervious. The first and second sheets of relatively flexible material have surfaces formed from a fluid, impervious plastic material. In one embodiment of the invention, the plurality of sidewall panel portions comprise a back panel portion, a right side panel portion, a front panel portion and a left side panel portions and the glue tab panel portion extends outwardly form one of the left side and right side panel portions.
A carton is formed from the above described carton blank by folding the sidewall panel portions and the glue tab panel portion around the fold lines therebetween, securing the glue tab panel portion to one of the sidewall panel portions, sealing together the facing surfaces of the second sheet of relatively flexible material, folding the bottom panel portions into superposed relationship and securing them together, filling the carton with a desired material, sealing together portions of the facing surfaces of the first sheet of relatively flexible material and folding the top panel portions into superposed relationship and securing them together to form a leakproof carton. In one embodiment of the invention, the plurality of sidewall panel portions comprise a back panel portion, a right side panel portion, a front panel portion and a left side panel portion, and the glue tab panel portion is secured to the back panel portion. However, such one embodiment is for illustration purposes only and the carton blank can be of other configurations. The method further comprises securing the portions of said first and second sheets of relatively flexible material extending upwardly and downwardly from said glue tab panel portion to portions of the first and second sheets of relatively flexible material extending upwardly and downwardly from said the back panel portion.
In another preferred embodiment of the invention, the carton blank is the same as that described above except for the location of the first and second sheets of a relatively flexible material. The first sheet of a relatively flexible material has an upper edge, a central body portion and a lower edge and the first securing means secure portions of the central body portion adjacent to the upper edge to the portions of the sidewall panel portions and the portion of the glue tab panel portion. The second sheet of a relatively flexible material has an upper edge, a central body portion and a lower edge and the second securing means secure portions of the central body portion adjacent to the lower edge to the other portions of the sidewall panel portions and the other portion of the glue tab panel portion. The method of forming a carton from the another preferred carton blank comprises folding the remaining portion of the central body portion of the first sheet of relatively flexible material over the first securing means until the remaining portion is in superposed relationship over the first securing means, the top panel portions and the portion of the glue tab portion, folding the remaining portion of the second sheet of relatively flexible material over the second securing means portion thereof until the remaining portion is in superposed relationship over the second securing means, the bottom panel portions and the another portion of the glue tab panel portion, folding the sidewall panel portions and the glue tab panel portion around the fold lines therebetween, securing the glue tab panel portion to one of the sidewall panel portions, sealing together the lowermost portion of the facing surfaces of the second sheet of relatively flexible material, folding the bottom panel portions into superposed relationship and securing them together, filling the carton with a desired material, sealing together the uppermost portions of the facing surfaces of the first sheet of relatively flexible material and folding the top panel portions into superposed relationship and securing them together to form a leakproof carton.
In another preferred embodiment of the invention, the carton blank comprises a unitary sheet of a relatively rigid material, such as paperboard, having an inner surface and an outer surface and a left side edge, a right side edge, a top edge and a bottom edge with the left and right side edges being perpendicular to the top and bottom edges. The unitary sheet of relatively rigid material has a plurality of cut and fold lines for dividing the unitary sheet of relatively rigid material into a plurality of sidewall panel portions, a glue tab panel portion, and top and bottom panel portions extending outwardly from the sidewall panel portions. A first strip of a relatively flexible material, such as paper, having an inner surface and an outer surface is superposed over the inner surface of the top panel portions and portions of the sidewall panel portions adjacent to but spaced from the fold lines between them and the top panel portions and a portion of the inner surface of the glue tab panel portion. A second strip of a relatively flexible material, such as paper, having an inner surface and an outer surface is superposed over the inner surface of the bottom panel portions, and other portions of the sidewall panel portions adjacent to the fold lines between them and the bottom panel portions and another portion of the inner surface of the glue tab panel portion. A continuous coating of a plastic material, such as polyethylene, covers the inner surfaces of the first and second strips of relatively flexible material and the remaining portions of the inner surfaces of the plurality of sidewall panel portions and the glue tab panel portion and holds the first and second strips of a relatively flexible material in the desired relationship with the unitary sheet of a relatively rigid material. The first strip of a relatively flexible material has an upper edge, a central body portion and a lower edge. If desired, first securing means are used to secure portions of the central body portion adjacent to the lower edge to the portions of the sidewall panel portions adjacent to but spaced from the fold lines between them and the top panel portions the portion of the glue tab panel portion. The second strip of a relatively flexible material has an upper edge, a central body portion and a lower edge. If desired, second securing means are used to secure portions of the central body portion adjacent to the upper edge to the portions of the sidewall portions adjacent to but spaced from the fold lines between them and the bottom panel portions and the another portion of the glue tab panel portion.
In another preferred embodiment of the invention, the carton blank comprises a unitary sheet of a relatively rigid material, such as paperboard, having an inner surface and an outer surface and a left side edge, a right side edge, a top edge and a bottom edge with left and right side edges being perpendicular to the top and bottom edges. The unitary sheet of relatively rigid material has a plurality of cut and fold lines for dividing the unitary sheet of a relatively rigid material into a plurality of sidewall panel portions, a glue tab panel portion and top and bottom panel portions extending outwardly from the sidewall panel portions. A sheet of relatively flexible plastic material, such as polypropylene, is superposed over the inner surface of the unitary sheet of relatively rigid material. First securing means extend between the right side edge and the left side edge of the sheet of a relatively rigid material and secure a first portion of the sheet of a relatively flexible plastic material to the portions of the inner surfaces of the sidewall panel portions located between but spaced from the fold lines between them and the top and bottom panel portions and a first portion of the glue tab panel portion. A first sheet of a relatively flexible material, such as paper, is secured to a second portion of the sheet of relatively flexible plastic material and is superposed over the top panel portions and the portions of the inner surfaces of the sidewall panel portions between the first portion of the sheet of relatively flexible material and the fold lines between them and the top panel portions and a second portion of the glue tab panel portion. A second sheet of a relatively flexible material, such as paper, is secured to a third portion of the sheet of a relatively flexible plastic material and superposed over the bottom panel portions and the portions of the inner surfaces of the sidewall panel portions between the first portion of the sheet of relatively flexible plastic material and the fold lines between them and the bottom panel portions and a third portion of the glue tab panel portion.
In another preferred embodiment of the invention, the carton blank comprises a unitary sheet of a relatively rigid material, such as paperboard, having an inner surface and an outer surface and a left side edge, a right side edge, a top edge and a bottom edge. The unitary sheet of a relatively rigid material has a plurality of cut and fold lines for dividing the unitary sheet of a relatively rigid material into at least a plurality of sidewall panels portions, a glue tab panel portion, a closure panel and end panels portions. A unitary sheet of a relatively flexible material is superposed over and secured to the outer surfaces of the at least a plurality of the sidewall panel portions, the end panel portions, the closure panel and only a portion of the glue tab panel portion so that the remaining portion of the outer surface of the glue tab panel portion is exposed. The unitary sheet of a relatively flexible material is non-compatible to the use of a water based adhesive so that an effective seal between the unitary sheet and the paperboard material cannot be formed. The relatively flexible material can be a plastic material or other materials having similar characteristics, such as paper surface coated with a plastic material. A carton is formed from the carton blank described above by folding the sidewall panels portions around the fold lines securing the end panels portions together, filling the carton and adhesively securing the exposed outer surface of the glue tab panel portion to a portion of the inner surface of the closure panel portion using a water based adhesive.
In another preferred embodiment of the invention, the apparatus for forming a laminate of materials for use in forming the carton blanks comprises a pair of laminating rolls having facing portions to form a nip therebetween. First feeding means are provided for feeding a continuous strip of a relatively rigid material, such as paperboard, into the nip. Second feeding means are provided for feeding a plurality of spaced apart, relatively narrow continuous strips of a relatively flexible material, such as paper, in spaced apart superposed relationship over portions of the continuous strip of relatively rigid material into the nip. Means are provided for applying a liquid plastic material, such as polyethylene, over exposed surfaces of the plurality of spaced apart, relatively narrow continuous strips of a relatively flexible material and the strip of relatively rigid material as they enter the nip and also to form a pool of the liquid plastic material in the nip to ensure an even coating. Third feeding means are provided for feeding a continuous film of a relatively flexible plastic material into the nip to secure the continuous film of a relatively flexible plastic material to the coated exposed surfaces of the spaced apart, relatively narrow continuous strips of relative flexible material and the exposed surface of the continuous strip of relatively rigid material.
In another preferred embodiment, the method further comprises removing the continuous strips of relatively flexible material and the portions of the film of a relatively flexible material secured thereto from the laminate to leave exposed portions of the continuous strip of a relatively rigid material.
In another preferred embodiment of the invention, the method for forming a laminate of materials for use in forming carton blanks using at least a pair of rotating laminating rolls comprises feeding a continuous strip of a relatively rigid material into the nip between the rotating laminating rolls, feeding a plurality of spaced apart, relatively narrow continuous strips of a relatively flexible material into the nip in spaced apart superposed relationship over portions of the continuous strip of relatively rigid material and applying a liquid plastic material over the exposed surfaces of the plurality of continuous strips of a relatively flexible material and the continuous strip of a relatively rigid material as they enter the nip, as described above, to provide a continuous surface of the plastic material and to hold the plurality of continuous strips of a relatively flexible material in superposed relationship over portions of the continuous strip of a relatively rigid material.
In another preferred embodiment of the invention, a continuous strip of a relatively rigid material, preferably paperboard, is fed between a driven gravure roll and an idler roll and a continuous layer of adhesive is applied to the central body portion of the continuous strip of a relatively rigid material. Although a gravure roll is disclosed, it is understood that any conventional apparatus can be used to apply the adhesive. A continuous film of a relatively flexible, fluid impervious material, preferably plastic, is laminated onto the continuous strip of a relatively rigid paperboard material by passing them into the nip between first and second laminating rolls so that the central body portion of the continuous film of a relatively flexible plastic material is adhesively secured to the central body portion of the continuous strip of a relatively rigid paperboard material. The laminated continuous strip of a relatively rigid paperboard material and the continuous film of a relatively flexible material is passed through carton blank forming apparatus to produce carton blanks having cut and fold lines. Although only one gravure roll is described it is understood that a plurality of gravure rolls can be mounted to produce a plurality of laminated continuous strips of a relatively rigid paperboard material and continuous films of a relatively flexible material. The relatively flexible material is fluid impervious. If desired, a plurality of spaced apart, relatively narrow continuous strips of a relatively flexible material, such as paper, can be fed into the nip between the gravure roll and the idler roll. In this embodiment, the gravure roll is patterned to apply an adhesive coating to the exposed surfaces of the plurality of spaced apart, relatively narrow continuous strips of a relatively flexible material and the continuous strip of a relatively rigid material so that the plurality of spaced apart, relatively narrow continuous strips of a relatively flexible material and portions of the continuous strip of a relatively rigid material can be secured to the continuous strip of a relatively flexible fluid impervious material.
The carton blank formed from the above described process wherein only the continuous strip of a relatively rigid material and the continuous strip of a relatively flexible material are laminated together comprises a unitary sheet of relatively rigid material having an inner surface, an outer surface, a left side edge, a right side edge, a top edge and a bottom edge. The unitary sheet of a relatively rigid material has a plurality of cut and fold lines for dividing the unitary sheet of a relatively rigid material into a plurality of sidewall panels portions, a glue tab panel portion, and top and bottom panels portions joined to the sidewall panels portions by fold lines. The central body portion of a rectangular sheet of a relatively flexible fluid impervious material is adhesively secured to the central body portion of the plurality of sidewall panels portion and the glue tab panel portion. The adhesive securements terminate at locations adjacent to but spaced from the fold lines between the plurality of sidewall panels portions and the top and bottom panels portions. The rectangular sheet of a relatively flexible material has a left side edge, a right side edge, a top edge and a bottom edge which coincide with the similar edges of the unitary sheet of a relatively rigid material. A carton is formed by folding the plurality of sidewall panels portions and the glue tab panel portion around the fold lines therebetween and securing the glue tab panel portions to one of the sidewall panels portions. The superposed portions of the rectangular sheet of a relatively flexible plastic material extending downwardly from the glue tab panel portion and the sidewall panel portions are secured together in a conventional manner. The bottom panels portions are folded and secured together. The carton is then filled with a desired material. A conventional top closure of the portions of the rectangular sheet of a relatively flexible fluid impervious material extending upwardly from the sidewall panels and the glue table panel is made and the top panels portions are folded and secured together.
In another preferred embodiment of the invention, the apparatus for forming a laminate of materials comprises a driven coating applicator roll, such as a gravure roll, mounted at a fixed location for rotational movement. The coating applicator roll has a raised body portion for use in transferring coating materials. Coating means are provided for applying an adhesive coating to the raised body portion. An idler roll is mounted for rotational movement and for applying pressure on the raised body portion. First feeding means are provided for feeding a continuous film of a relatively flexible fluid impervious material between the coating applicator roll and the idler roll to apply a coating of adhesive on the continuous film of a relatively flexible fluid impervious material. First and second rolls are mounted at a fixed location and one or both of them are driven. Second feeding means are provided for feeding the adhesive coated continuous film of a relatively flexible fluid impervious material, a plurality of spaced apart, relatively narrow continuous strips of a relatively flexible material and a continuous strip of a relatively rigid material between the first and second rolls to laminate and secure together the plurality of spaced apart, relatively narrow continuous strips of a relatively flexible material to portions of the adhesive coated continuous film of a relatively flexible fluid impervious material and portions of the continuous strip of a relatively rigid material to other portions of the continuous film of a relatively flexible fluid impervious material. Processing apparatus are provided for further processing said laminated materials. The coating applicator roll applies the adhesive coating to the bottom surface of the continuous film of a relatively flexible fluid impervious material and inverting means are provided for inverting the continuous film of a relatively flexible fluid impervious material so that the bottom surface becomes a top surface. If desired, the plurality of continuous strips of a relatively flexible material are not used and the applicator roll is patterned to apply the coating material only to the central body portion of the continuous strip of a relatively flexible fluid impervious material.
In one embodiment of the invention, the raised body portion comprises the entire outer surface of the applicator roll. In another embodiment of the invention, the raised body portion comprises two circumferentially extending edge portions and a plurality of spaced apart axially extending portions extending into the two circumferentially extending edge portions.
When the plurality of continuous strips of a relatively flexible material comprise at least two spaced apart strips having substantially the same width and at least one strip centrally located between the at least two spaced apart strips and having a width twice as great as the width of either of the at least two spaced apart strips, the method further comprises cutting the at least one strip in half to form two continuous strips of the laminated material each having a central body portion comprising laminated portions of the continuous strip of a relatively rigid material and the relatively flexible fluid impervious material and opposite edge portions, each of the opposite edge portions comprising laminated portions of the relatively flexible fluid impervious material and the continuous strip of the relatively flexible material overlying edge portions of the continuous strip of a relatively rigid material.
The method further comprises folding the opposite edge portions of the laminated portions of the relatively flexible fluid impervious material and the continuous strip of a relatively flexible material over portions of the central body portion and forming cut lines in the edge portions of the continuous strip of a relatively rigid material to provide for top and bottom panel portions.